Magmatic Activity And Carbon Cycle Of Typical Seamount In Western Pacific Ocean

Global carbon cycle,as a global surface-deep exchange process,has an importantcontrolling effect on the global climate and the evolution of the Earth's spheres,and there is a close relationship between alkaline OIBs and the global carbon cycle,making alkaline OIBs as an ideal material for studying the global carbon cycle.The Western Pacific has the oldest oceanic crust,the densest distribution of seamounts,and wide distribution of alkali basalts,which has a natural advantage for studying alkaline OIBs.Therefore,in this study,we collected alkaline OIBs from Kocebu Seamount,where rock samples have not been collected yet.The chemical composition of bulk rock and mineralogical characteristics of these samples were studied.We found that alkaline OIBs of this area have higher Ca O and P₂O₅,lower SiO₂ content,high field strength element(HFSE)negative anomaly,more distinctly K negative anomaly and the ubiquity of titanaugite,which indicate a carbonate rich mantle source.Based on the relatively high TiO₂ contents and La/Yb ratios,low Mg O contents suggest that the volcanic rocks of this area could have been derived from a mantle source with carbonated eclogite.